The present invention relates generally to the structure and use of surgical instruments. More particularly, the present invention relates to an actuator handle for surgical instruments, in particular, electrosurgical and other interventional instruments for use in least invasive surgical procedures.
Least invasive surgical (LIS) techniques, such as laparoscopy, endoscopy, artheroscopy, thoracoscopy, and pelviscopy, are generally performed through small incisions using specialized instruments to perform desired surgical procedures. Usually, the instruments are introduced through a tube, such as a cannula or trocar sleeve, while the physician observes manipulation of the instruments through specialized imaging equipment, such as laparoscopes, endoscopes, thoracoscopes, and artheroscopes. Such LIS techniques offer significant advantages over conventional "open" surgical procedures. In particular, the LIS techniques are usually less traumatic, require a shorter recovery time, and are less costly than the corresponding conventional surgical techniques.
During LIS procedures, it is frequently necessary to cauterize, sever, ablate or otherwise manipulate tissue using an electrosurgical instrument. Electrosurgical instruments apply electrical energy to body tissue to change the structure or function of the tissue or body organ. Typically, electrosurgical devices apply very high frequency current to excise tissue and/or close small bleeding blood vessels by electrocauterization. Of particular interest to the present invention are monopolar electrosurgical devices, where the patient is grounded and very high frequency electrical current is applied to a body organ or a desired area of tissue using a specialized electrode. Electrosurgical procedures are particularly advantageous since they reduce bleeding from small blood vessels, facilitating the handling of highly vascularized tissues while minimizing exposure of the patient to shock and pain.
Of further interest to the present invention are electrosurgical instruments having reciprocating elements at their distal end to facilitate cauterization and/or cutting of tissue. Electrosurgical instruments having a surgical hook at their distal end with a paddle element mounted to axially reciprocate relative to the hook are described in co-pending application Ser. No. 07/692,809, assigned to the assignee of the present invention, the complete disclosure of which is incorporated herein by reference. In such devices, a body structure may be positioned within the surgical hook, which is electrically coupled to an electrosurgical generator. Electrical energy may be applied through the hook to the body structure to effect cauterization or cutting. At the same time, the paddle element may be axially reciprocated relative to the hook to engage the body structure. The paddle element may also be coupled to the electrosurgical generator, allowing electric current to be delivered to the body structure through the paddle element as well as the hook. The paddle element may thereby be used to assist in the cutting or cauterization of tissue. The paddle element is further useful in providing a flat, paddle-shaped electrode surface useful for cauterizing, cutting, or otherwise manipulating various tissue structures. In addition, the paddle element is useful for cleaning charred tissue and other debris from the surgical hook by reciprocating the paddle element relative to the hook to engage and remove such debris.
In electrosurgical instruments like those just described, a handle is provided at the proximal end of the device which can be grasped by the surgeon to position, manipulate and actuate the device. Such a handle desirably has a shape and size suitable for grasping with a single hand, and must include both an actuator for reciprocating the paddle element, as well as pigtail connector to connect the surgical hook and/or paddle element to an electrosurgical power supply. In addition, such handles may include an aspiration port for aspirating the treatment site or delivering a therapeutic agent, flushing liquid or other fluid through the device to the treatment site.
Additional LIS instruments of interest to the present invention are fascia cutters such as those described in copending application Ser. No. 07/757,170, assigned to the assignee of the present invention, the complete disclosure of which is incorporated herein by reference. Such fascia cutting instruments are used for various purposes including enlargement of abdominal penetrations and other surgical incisions through the fascia transversalis. Such enlargement is sometimes necessary during laparoscopic cholecystectomy procedures, where the gallbladder is surgically severed and withdrawn through a small cannula. Complications sometimes arise when the gallbladder is enlarged or contains gallstones which are too large to be drawn through the cannula. In such cases, it is necessary to remove the cannula and to enlarge the abdominal penetration so as to allow the gallbladder to be withdrawn through the penetration. The fascia cutting instrument described in co-pending application Ser. No. 07/757,170 comprises an elongate shaft having a transverse slot near its distal end in which the fascial layer may be received. The instrument has an axially reciprocating blade which may be translated across the slot to sever the fascial tissue, resulting in an enlarged penetration. The instrument includes a handle at its proximal end which is gripped by the surgeon to position the shaft in the penetration and manipulate the slot about the fascial layer. An actuator is coupled to the handle for selective reciprocation of the blade. The blade may further be coupled to an electrosurgical generator through pigtail connector on the handle to provide cauterization and enhanced cutting.
In addition to the instruments just described, any type of LIS or conventional surgical instrument which utilizes a handle for grasping and manipulating the instrument, as well as an actuator on the handle for selectively actuating the moving components of the device will be of interest to the present invention. Such instruments include, for example, surgical scissors, graspers, retractors, needle holders and the like.
The use of surgical instruments like the forementioned during LIS procedures can be problematic due to the difficulty in positioning and manipulation such instruments within a body cavity through a trocar sleeve or other cannula. In order to reach the area of interest, such instruments frequently have elongated shafts which can be inserted through a cannula and which have sufficient length to reach the treatment site. However, such elongated instruments are difficult to maneuver smoothly and precisely. In addition, once an instrument has been positioned near the treatment site, the surgeon must actuate the device, typically by moving a lever, trigger, slide or other such actuator on the handle of the device. Current handle designs for LIS instruments frequently require the surgeon to change hand positions to manipulate and actuate the device. Moreover, known LIS instrument handles frequently employ actuators which require awkward hand position for actuation at the various angles at which such instruments may be disposed during a procedure. In addition, current handle designs often include laterally protruding hand grips, levers, triggers and the like, which can interfere with personnel and equipment in the vicinity of the device.
For these and other reasons, an actuator handle for LIS instruments is desired which will overcome the problems of known handle designs. In particular, the actuator handle should be ergonomically designed to facilitate a firm and convenient grip on the device at various angles. The actuator handle should employ an actuator which is operable using natural hand positions, in particular, hand positions which may also be used to manipulate and position the device, obviating the need for frequent changes of hand position. The actuator should further be integrated into the handle with minimal protrusion, so as to minimize interference with personnel or equipment in the vicinity. Particularly desirable is an actuator handle which is useful in connection with electrosurgical instruments, particularly those having a movable or reciprocating element in addition to a bipolar or monopolar electrode. For use with such instruments, the actuator handle should have means for connecting the electrode to an electrosurgical power supply, as well as an actuator for actuating the movable element. The actuator handle should be further adaptable for use in fascia cutting instruments. The actuator handle should not be limited to electrosurgical or fascia cutting devices, however, and should be useful in connection with a variety of LIS and conventional surgical instruments.